Conditionals, Inference, and Evidentiality Karolina Krzy zanowska - - PowerPoint PPT Presentation

Introduction Experiments Discussion

Conditionals, Inference, and Evidentiality

Karolina Krzy˙ zanowska Sylvia Wenmackers Igor Douven Sara Verbrugge Logic & Cognition Workshop ESSLLI 2012

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Outline

1

Introduction Conditionals Inference Evidentiality

2

Experiments Motivation Method Results

3

Discussion

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Conditionals

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Conditionals

What’s wrong with them?

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Conditionals

What’s wrong with them? (1) If badgers are cute, then 4+7=11. (2) If 23+45=8, then the world will end next year. (3) If dogs are people’s best friends, then they have four legs.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

What links a conditional’s antecedent and its consequent?

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

What links a conditional’s antecedent and its consequent?

an inference from a conditional’s antecedent to its consequent. conditionals as “condensed arguments” (Woods 2003).

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

An old philosophical idea

A conditional is true if and only if it corresponds to a valid argument (Chrysippus).

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Inference

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

inference certain uncertain induction abduction deduction

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Classifying conditionals

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Classifying conditionals

subjunctive vs. indicative conditionals

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Classifying conditionals

subjunctive vs. indicative conditionals content vs. inferential conditionals

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Classifying conditionals

subjunctive vs. indicative conditionals content vs. inferential conditionals

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

A new typology of inferential conditionals

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

A new typology of inferential conditionals

certain:

deductive inferential conditionals

uncertain:

inductive inferential conditionals abductive inferential conditionals

Igor Douven and Sara Verbrugge (2010), The Adams family. Cognition 117, 302–318.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Inferential conditionals

Definition A sentence “If p, then q” is a deductive inferential (DI) / inductive inferential (II) / abductive inferential (AI) conditional iff q is a deductive / inductive / abductive consequence of p.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Inferential conditionals

Definition A sentence “If p, then q” is a deductive inferential (DI) / inductive inferential (II) / abductive inferential (AI) conditional iff q is a deductive / inductive / abductive consequence of p. Definition A sentence “If p, then q” is a contextual DI / II / AI conditional iff q is a deductive / inductive / abductive consequence of {p, p1, . . . , pn}, with p1, . . . , pn being background premises salient in the context in which p → q is asserted or being evaluated.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Examples of DI conditionals

(4) If all Indian elephants have small ears and Babou is an Indian elephant, then Babou has small ears.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Examples of DI conditionals

(4) If all Indian elephants have small ears and Babou is an Indian elephant, then Babou has small ears. Context: All Indian elephants have small ears. (5) If Babou is an Indian elephant, then it has small ears.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Examples of II conditionals

(6) If 95% of students pass this exam, you will pass as well.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Examples of II conditionals

(8) If 95% of students pass this exam, you will pass as well. Context: Bernard is a bit of an irregular student: sometimes he works hard, but he can also be lazy. So far he had excellent grades for most courses for which he had worked hard. (9) If Bernard works hard for the linguistics course, then he will get an excellent grade for it.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Examples of AI conditionals

(7) If David is coughing and sneezing, then he caught an infection.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Examples of AI conditionals

(7) If David is coughing and sneezing, then he caught an infection. Context: Nelly lives on the sixth floor of an apartment building. The elevator has been broken since earlier this morning. A good friend of Nelly’s who lives on the third floor of the same building hears someone rushing down the stairs. She knows that Nelly tends to avoid exercise as much as possible. (8) If that’s Nelly rushing down the stairs, then she is in a hurry.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Evidentiality

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Evidentiality

Monitoring source and quality of the evidence

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Evidentiality

Monitoring source and quality of the evidence Various markers of evidentiality:

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Evidentiality

Monitoring source and quality of the evidence Various markers of evidentiality:

grammatically encoded (prefixes, suffixes, etc.)

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Evidentiality

Monitoring source and quality of the evidence Various markers of evidentiality:

grammatically encoded (prefixes, suffixes, etc.) lexical markers (“I saw”, “I heard”, “allegedly” etc.)

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Evidentiality

Monitoring source and quality of the evidence Various markers of evidentiality:

grammatically encoded (prefixes, suffixes, etc.) lexical markers (“I saw”, “I heard”, “allegedly” etc.)

Willett’s categorisation.

Thomas Willett (1988), A cross-linguistic survey of the grammaticization of

• evidentiality. Studies in Language 12(1), 51–97.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Basic categories of evidentiality (Willett 1988)

access direct indirect hearsay inference perception

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Basic categories of evidentiality (Willett 1988)

access direct indirect hearsay inference perception

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Candidates for inferential markers “must”

and

“should”

Kai von Fintel and Anthony Gillies (2007), An Opinionated Guide to Epistemic

• Modality. Oxford Studies in Epistemology 2, 32-63.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Markers of inference

(9) a. Susan studied philosophy. She should know who Hegel was.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Markers of inference

(9) a. Susan studied philosophy. She should know who Hegel was.

• b. ? Susan just published a book on Hegel. She should know

who Hegel was.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Markers of inference

(9) a. Susan studied philosophy. She should know who Hegel was.

• b. ? Susan just published a book on Hegel. She should know

who Hegel was. (10) a. I heard Jim got a post-doc position. He must have already defended his PhD.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Markers of inference

(9) a. Susan studied philosophy. She should know who Hegel was.

• b. ? Susan just published a book on Hegel. She should know

who Hegel was. (10) a. I heard Jim got a post-doc position. He must have already defended his PhD.

• b. ? I attended Jim’s public PhD defence last month. He

must have already defended his PhD.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Markers of inference

(9) a. Susan studied philosophy. She should know who Hegel was.

• b. ? Susan just published a book on Hegel. She should know

who Hegel was. (10) a. I heard Jim got a post-doc position. He must have already defended his PhD.

• b. ? I attended Jim’s public PhD defence last month. He

must have already defended his PhD. (11) a. The key is either in my pocket or in the bag. It is not in my pocket, so it must be in the bag.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality

Markers of inference

(9) a. Susan studied philosophy. She should know who Hegel was.

• b. ? Susan just published a book on Hegel. She should know

who Hegel was. (10) a. I heard Jim got a post-doc position. He must have already defended his PhD.

• b. ? I attended Jim’s public PhD defence last month. He

must have already defended his PhD. (11) a. The key is either in my pocket or in the bag. It is not in my pocket, so it must be in the bag.

• b. ? I see that the key is in the bag, so it must be in the bag.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality 1 Are “must” and “should” really inferential markers? Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality 1 Are “must” and “should” really inferential markers? 2 Do they mark any inference? Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Conditionals Inference Evidentiality 1 Are “must” and “should” really inferential markers? 2 Do they mark any inference? 3 Can they serve as “litmus papers”? Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

The Experiment

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Questions

1 How does adding an evidential marker to an inferential

conditional’s consequent affect its assertability?

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Questions

1 How does adding an evidential marker to an inferential

conditional’s consequent affect its assertability?

2 Is the pattern common for different languages? Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Method

three versions of the survey: English (N = 95), Dutch (N = 47) and Polish (N = 42) all participants were native speakers. the type of conditional (DI / II / AI) as well as lexical markers were manipulated within subjects. each participant were presented with 15 contexts: 5 involved deductive inference, 5 involved inductive inference, and 5 involved abductive inference. each context was followed by 3 conditional sentences: one without any marker, one with “should” / “powinien” / “zal wel”, and one with “must” / “musi” / “moet wel”. 7-point scale of assertability.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Example stimulus: deductive inference

Context: All Indian elephants have small ears.

How assertable are the following conditionals given this context?

If Babou is an Indian elephant, then it has small ears. If Babou is an Indian elephant, then it should have small ears. If Babou is an Indian elephant, then it must have small ears.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Example stimulus: inductive inference

Context: Bernard is a bit of an irregular student: sometimes he works hard, but he can also be lazy. So far he had excellent grades for most courses for which he had worked hard.

How assertable are the following conditionals given this context?

If Bernard works hard for the linguistics course, then he will get an excellent grade for it. If Bernard works hard for the linguistics course, then he should get an excellent grade for it. If Bernard works hard for the linguistics course, then he must get an excellent grade for it.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Example stimulus: abductive inference

Context: Nelly lives on the sixth floor of an apartment building. The elevator has been broken since earlier this morning. A good friend of Nelly’s who lives on the third floor of the same building hears someone rushing down the stairs. She knows that Nelly tends to avoid exercise as much as possible.

How assertable are the following conditionals given this context?

If that’s Nelly rushing down the stairs, then she is in a hurry. If that’s Nelly rushing down the stairs, then she should be in a hurry. If that’s Nelly rushing down the stairs, then she must be in a hurry.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Results

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

What did we measure?

Relative assertability = assertability with a marker minus assertability without a marker.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Results: English linguistic markers

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Results: Polish linguistic markers

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results

Results: Dutch linguistic markers

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results 1 English “must” and “should” are inferential markers.

“should” is a marker of inductive inference. “must” is a marker of abductive inference.

2 Polish “musi” is a marker of abductive inference. 3 The role of Polish “powinien” is unclear. Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results 1 English “must” and “should” are inferential markers.

“should” is a marker of inductive inference. “must” is a marker of abductive inference.

2 Polish “musi” is a marker of abductive inference. 3 The role of Polish “powinien” is unclear. 4 Dutch “moet wel” is a marker of abductive inference. 5 Dutch “zal wel” seems to mark only uncertainty. Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion Motivation Method Results 1 English “must” and “should” are inferential markers.

“should” is a marker of inductive inference. “must” is a marker of abductive inference.

2 Polish “musi” is a marker of abductive inference. 3 The role of Polish “powinien” is unclear. 4 Dutch “moet wel” is a marker of abductive inference. 5 Dutch “zal wel” seems to mark only uncertainty. 6 Additional support for the claim that the typology of

conditionals proposed by Douven and Verbrugge (2010) is of theoretical significance.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Discussion

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Polish “powinien” vs. English “should”

In Polish, a normative interpretation of the modal verb “powinien” (“should”) seems to be more salient than in English or in Dutch.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Polish “powinien” vs. English “should”

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Polish “powinien” vs. English “should”

Context: A pharmaceutical company unexpectedly got into financial trouble. They had to cut many jobs and decided to fire almost all employees above 50. Mark is an employee of this company.

How assertable are the following conditionals given this context?

If Mark is above 50, then he should be among the employees who will be fired.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Example stimulus: inductive inference

Context: Bernard is a bit of an irregular student: sometimes he works hard, but he can also be lazy. So far he had excellent grades for most courses for which he had worked hard.

How assertable are the following conditionals given this context?

If Bernard works hard for the linguistics course, then he should get an excellent grade for it.

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality

Introduction Experiments Discussion

Thank you!

Krzy˙ zanowska, Wenmackers, Douven, Verbrugge Conditionals, Inference, and Evidentiality